| // Copyright 2016 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #ifndef WorkerThreadLifecycleObserver_h |
| #define WorkerThreadLifecycleObserver_h |
| |
| #include "core/CoreExport.h" |
| #include "platform/LifecycleObserver.h" |
| |
| namespace blink { |
| |
| class WorkerThreadLifecycleContext; |
| |
| // An interface for observing worker thread termination from the main thread. |
| // This may be useful, for example, when an object living on the main thread |
| // needs to release references to objects on the worker thread before it gets |
| // terminated. |
| // |
| // A class that inherits this interface should override |
| // LifecycleObserver::contextDestroyed() that is called on the main thread when |
| // the worker thread is about to terminate. While contextDestroyed() is called, |
| // it is guaranteed that the worker thread is still alive. |
| // |
| // A newly created observer should firstly check whether the worker thread is |
| // alive by wasContextDestroyedBeforeObserverCreation(). If this return true, |
| // the worker thread has already been terminated before the observer is created, |
| // and contextDestroyed() is never notified. |
| class CORE_EXPORT WorkerThreadLifecycleObserver |
| : public LifecycleObserver<WorkerThreadLifecycleContext, |
| WorkerThreadLifecycleObserver> { |
| public: |
| virtual void contextDestroyed(WorkerThreadLifecycleContext*) {} |
| |
| protected: |
| explicit WorkerThreadLifecycleObserver(WorkerThreadLifecycleContext*); |
| virtual ~WorkerThreadLifecycleObserver(); |
| |
| bool wasContextDestroyedBeforeObserverCreation() const { |
| return m_wasContextDestroyedBeforeObserverCreation; |
| } |
| |
| private: |
| const bool m_wasContextDestroyedBeforeObserverCreation; |
| }; |
| |
| } // namespace blink |
| |
| #endif // WorkerThreadLifecycleObserver_h |